It is often desirable to be able to fill successive containers with product automatically, rapidly, neatly and with a predetermined amount of product.
For well-known and obvious reasons, the containers to be filled preferably move rapidly in a continuously-moving series train, rather than stopping to be filled and then starting up again. It is also often desirable to employ a so-called volumetric filler for this purpose, which uses a cylinder containing a piston to dispense a predetermined amount of product upon each stroke of the piston.
One form of such apparatus is described and claimed in U.S. Pat. No. 3,731,715 of L. M. Gageant and William L. Greet, issued May 8, 1973 and originally filed May 29, 1969, which is of common assignee herewith. It comprises a so-called rotary-turret volumetric filler, in which the containers are filled while moving in a circle, with the dispensers moving in a circle above them. In such apparatus the containers are forced to deviate from a straight-line path on an input conveyor so as to enter the circular path for filling, and to resume a straight-line path upon their exit from the rotary filler.
In such a rotary volumetric filler, it is also known to empty the dispenser cylinders into the containers as they move along one part of their circular path as described above, and to fill the dispenser cylinders with product while they are traversing a different part of their path. Filling may be accomplished by sliding the lower open ends of the dispenser cylinders along a feed plate containing a slot-like opening in its top, through which the product is fed into the lower ends of the cylinders from a chamber below the slot, as a piston in each cylinder is drawn upwardly. A continuous sealing surface is also provided between the cylinders, which moves with the cylinders and in contact with the feed plate, so that the product cannot rise upwardly through the slot and between the cylinders.
Another form of rotary filler is described in application Ser. No. 768,352 of W. A. von Lersner, filed Aug. 22, 1985, issued as U.S. Pat. No. 4,627,475 on Dec. 9, 1986, and of common assignee herewith.
While effective for its intended purposes, the rotary filler is limited with respect to the rate at which it can fill containers accurately and neatly at a high rate, since the containers must be diverted from a straight-line path, moved along a circle, and then returned to a straight-line path, operations which involve accelerations of the container and hence tend to produce spillage at high rates of operation.
While so-called "linear" systems which dispense product into containers as they move along a straight line are known, there do not appear to have been systems of this class which can be used effectively using high-speed volumetric fillers or the like.
Accordingly, it is an object of the invention to provide a new and useful linear filler system.
Another object is to provide such a linear filler system system using volumetric fillers.
A further object is to provide such a system which operates rapidly and accurately, with substantially no tendency to spillage of product even when operated at high rates.
Still another object is to provide such a linear filler system in which filling is accomplished by feeding product into the lower ends of the dispenser cylinders through an opening over which they slide as product is supplied to the opening from below the slot, while preventing product from being fed upwardly between the cylinders.